Internal screw thread lapping machine



July 3, 1945. A. M. BRAKE l INTERNAL SCREW THREAD LAPPING MACHINE 3 Sheets-Sheet l Filed April 19, 1943 July. 3, 1'945. A. M.V'DRAKE 2,379,693

' INTERNAL SCREW THREJVVL'APPING MACHINE Filed April 19, 1945 3 Sheetsf-Sheet 2 July 3 1945.

A. M. DRAKE 2,379,693

INTERNAL SCREW THREAD LAPPING MACHQINE 'l Filed April 19, 194s :s Sheng-sheet s Patented July 3, 1945 n t l l l @(01. 51-,-9]6) This Yinvention relates tri-lapping` meanings ,fo

member-for oscillati'ngthe member beingwl-appedioi `lapping thread `gagesor44 for lapping otheriimemj-f being alsoshown. f

bers having internal screwitlireads. i More particularly the inven-tionrrelates tje-9h31 Fig. 5'isanoutlinefdiagramoff'tire hydrant i ldallic'finechanism for rotating ya fthreadedil-lap- 5 Qmechanismior actuatingthe spindle'rotati'ornandm i mile toolpredetermined `numbersof'ievolutions`` reciprocating member; and j l f i injeacli vdirection Whilewengaged byfa :Work -pieeef Fig. 6 is a detail View yof the slideanri the-.resin being lapped, thereM being means tosimultanea ient `connections between the slide-'and the Lactua.. ously oscillate the Work 4piece v about-the axis"A of` tor for oscillating the-gagerai'id` gage'holdermamtsi f itslscreW threadsouring rotation ofilthelappin'g 910 `being shown' ingsectionrtomore clearlyhdisclosew i too1`ineach1directiontheir construction@ l l l Ar primary object of the `invention istoprfovideh Brey'alld in' tsbioadestaspectthe inenfon'm a machine having meansl to `rotate a lapping tool` mayicomprise-the following principal partszFirstm intheformyofa threaded member predetermined a .base ,having amotorf `driven-hydraulic@urinate numbers of revolutions" in eachjj direction about-1115 adapted to pump `a uid athiglr'fpressureintera.c itsaxis and to simultaneously'reciprocatea-meinh hydraulic system from a tank or sump prefeifaiblytl` berithrougn .any predetermined Ydistance in a di forming part of the base; second; a Workslwpolitirectionnormal to the` axis of thelappingc0011; ing and rotating spindle withinfsaidlbasesidpwem.. therenbeing interconnecting means betweentl'ief opposite directionsof rotationbydfluidimeansnf workpiece and the reciprocating member sothat' 20 third, a reciprocatingmember# actuatedwbyftluidie. the Work being lapped `may be oscillatedL through means. in` a direction `normal toi thetaxiso'fsslthee4 portionsof a revolution by; movementvof the real spindle on Whichfihe lappine tooliis'fmountedif ciprocatingmember; i l fourth,* reversing mechanismefonthefspindleiweM Another object of the inver'it-ion is'v toy provideV tating means voperative to successivelylreverse relief;j resilient inter-connecting-- means betW'eenLthe-#jz rotationof the spindle-afterpredetermined num-c, work' piece being lapped and the reciprocating `bersoi turnsuandffthya lholderlforftkirgitgage'ci member so that the reciprocating member' orslid'ef being lapped havinga member outstanding thereer` can accomplishits full' strokereglardless of ther'.` `from engaged Alov-*resilient menribers` `depending extent of oscillatory movement of 4the'Workpiece-V` from the' reciprocatingfmember totoscillaterthemr n Another object of the invention is to provi`de30 gage. being lappedduringfrotation ofthe lappingir` hydraulic'mechanisms` for controlling the speed y tool` and its spindle.` f i f ofK rotation and the `reversalsoi rotation 4of ther Referring mOre` jdetal `tothegurfe spindle' onwhich is mounted the lapping'tooland. .l l drawings, there -hasbeenshownwa duplex..l ftwrnf` tocontrol the speed of thel reciprocating memberf.- `spindle machine;V eachspindlepf whichpxand ts by means of which the Work piece isoscillatedwl "35 Vassociated-mechanism constitutes a completeila nd nallyjit is an object ofthe inventionrto'wA Ping unit ormachine. As-wi11-beiseenlinizFiga-ll providea holderpermitting size adjustment ofi-i and 2, the'lappingtOOlliSmountedsdetaoliablypal tnefscrew threadsbeing'lapped during-theiapping but fixedlyuponone -end of a horizontal-spindles.- operatfom v l A Il, therebeing'a collety I2 Tor-other formzof chuck;

Withtneabove and otner-objectsinviewrtne 40-for that purposel enabling lapping 4toelsLllJ ,to bea` slet-:thea

invention consists the features `of-construction substituted one-forfthe other or adjustrnentsmadae` andoperation set forth in the following SpQ'fCaof thelapr to "diiferentrotative :position-sr@ This tioi'if and illustrated in theaceomimnying;drawr spindle-ll is rotatably mounted wlthmrrhebaserw IISA.` n H; t 1 Qf the machine and may bewrotatedrbyany means,1 i Iii the drawings annexed heretofandjforminga 1 -45fsuchasby thel hydraulic imotor I4; directly; con-i l. part of this invention; nected in-alinement therewithw l i Figure lis a side elevation in section,shovving@` The motor |-3asshown isiof the `fluidttype andar a complete machine formingan embodiment*- of is operatedby meansofa hydrauliccircuit shownrrf; the present invention. in out1ine-in1F1gr 5. Amotor driven pumplhasia Fig,` 2 isla `front elevation, partlyin section, 50its intake 'connected t0l areturn-tankeli6r lleda, l showingthe parts of a 1duplex machine similar `with Waterioilor otherfluid and deliversthefluidzi totliatjshowninliigi. i under Ya suitable pressure-tol..a control valveal;

igisa irontelevatonfofa work pieceand Fromftliis -valv'e `I'Ifthe uid enters-the intakefofa its holden as shown in thepositionfassumed When-H a. distributing orwreversmg valveyl8ifromgawhichjc mounted'n tiie lapping tool; the reciprocating2-f55=the-i1u1d entersoneside ortheotherofthemotom cam disc 2| with the sD I3 depending upon the position of the distributing r valve I8. To actuate the distributing valve I8 a It Will be understood that in. the machine ;.1

shown in Figs. 1 and 2 in which two spindles II are provided there will be independently operatt ing motors I3, one for each spindle, and, corre' spondingly, there will be duplicate sets of valves" .II, I8 and I9 and cam discs 2| In order to rotate this spindle I I predetermined number of revolutions alternately in each direction, means are provided to drive the cam disc 2I having adjustablegdogs 2U mountedthereon fromthe spindle II. For this purpose a small gear22 is mounted directly on thespindle in mesh with a. large gear 23 onan intermediate shaft 24, there also being a worm 25 on this intermediate shaft,v In mesh with this Worm 25 isa worm wheel AZlion a shaft 21 having at its outer end .cam disc ZI With cams 29 adjustable angularly about its p e riphery. These cams 20 upon rotatiodrn the indle I I oscillate the control valve I9 to change the position. of Ythe dis, tributing valve 4I8 and the direction yof-A fli'i'id and'4. This chuck 50- has means for enclosing the member W to be lapped and preferably has means for manually making adjustments to vary the size of the threads being lapped during progress of the lapping operation. As this holder forms the subject matter of my copending application Serial No. 448,276, led June 24, 1942, now Patent No. 2,362,543, itis not thought that further description will be necessary.` Outstanding from the holder 50 is an arm 5I preferably "formed integrally with the holder and adapted to extend betweenv the two resiliently supported bars "i33idepending from the reciprocatory member 32.

Reciprocation, therefore, of the member 32 and the bars .33 'depending therefrom will cause oscily Llatory movements offthe holder 50 and the gage through the spindle rotating motor Y I3 so that each time thecontrolvalve I9 is shifted by one of the dogs 20` the rotation` of` the spindle I Ilwill be reversed. f l

Mounted upon the of the base 9 is a cylinder 3 ates `apiston 3l, the piston l slide 32, preferably and as shown in Figs( l and 2 which surrounds the cylinder 30. `.'llne cylinders 30 vforthe two parts of the machine may bein alinement and retained in position on the baseby being clamped `at their central portion as shown in Fig.- 2. `AA centrally, mountedl plug `29 divides the elongated member into twoxinclependent cylf inders 30. Reciprocation, there 3| Withinits cylinder l Depending'from thisslide`32 are twov bars 33 spaced a short distance apart t and v,depending from the lower portion of the slide to whichtliey are iiexibly attached by means of Suitable'light springs 34 so` that the bars 33 can ymove relative to the .slide 32 `against the,pressure., of ,thesve' springs 34. 1 Y

0 withinwlriich operas" being connected to a` To reciprocate the vslide 32 fluid under-pressure nds of the Cylinder... 30 through conduits, one of whichy is shown at 3a x isadmitted to the opposite e leading from separated portions offacvalvechamber 31. The valveV 38 within this chamber is moved to its operative positions-,toconnect a 4fluid supply conduit 39 witheitherof ,the connections,

to the cylinder 30 by means ofa rocker iIII) acting to movelthe valve 38 in one directionand aspring 4I to move the valve in theopposite d-irection.-

forvvard'and upper portion fore, of ra piston `3l) oscillates its slide 132.

To actuate the rocker III anA eccentricfilion fa I shaft 43 is rotated from the spindle .I`I' through gears 44 and 45. Preferably and-as indicated in` the diagram the fluid supply conduit te the cylin'f. der 30 may be connected to the pump I54fo r ro;-

To hold the `work piece while engaging thejlap y v70 L `tating the spindle II associated with the slide :325g

Illv onthe work spindle I I;,duringrthe;lappn operation it is. supported;- within, an adjustable chuckior holder 59 vshown most clearlyin Figs.ul3f

' W mounted therein.' Should the work piece W l tightly engage the lapping member III, movement mentary slide 52 housed within a endsdirectly to the supplementary slide 52. j

For convenience the supplementary .sliolef52". ythas hollow cylindrical portions slidable,within` a cylinder 55 securedin fixed positionwithin a depending portion of the slide 32.- To "indicate,

the amount of sliding movement of thefsupplel mentary slide 52, which indicates the 'amount o f` lapping being done, an indicator or pointer.' %'`lj `v may be provided on the supplementary'slide'l`52 movable adjacent a short scale 58.H In operation and with the dogs through any predetermined number ofk .revolutions and simultaneously the piston' 3 I vand its t slide 32 `Will be reciprocated. This reciprocatory movement of the slide 32wi11 take Vplace during rotation of the lapping tool .III so'that thework piece vW will be oscillated simultaneouslyiwith' rotationof the lapping tool. The strokeof-theflf slide 32 may be made such thatthe .maximum r practical length of oscillatory movement ,ofthe` gage holder 50 is effected.. This oscillatory move# ment, however, must be variable duringthe prog-. l ressV of the lapping operation and for differenti` types of work pieces. For that reason'thefre-zfsilif,

ent mounting for the supplementary slidj52 is provided and `the spring mounting for the barsz133.

It will bey understood that an abrasive compound will be supplied to the surface of. the'lapf ping tool I0 and periodically the holder 5Il'A for thegage W being lapped will `be adjustedv to close the threaded surface of the workpiece -W uponthe lapping toolIU so that lappin'gcan take place continuously and progressively 'lap Ithe threads on the work piece. t,

l. A machine for comprising in combination,` aibase,` ajspindle mounted for rotation therein; va lapping tool mounted on said spindle, rotatingfmaris forl said spindle, means to reverse thespindle rotationgar the length {Qf portionoffni'e. slide 32 `and held centrally therein by .means ich opposed springs 53. To. adjust the pressure` of these springs 53,` threaded members 54v having., hand Wheels 55 on their outer ends are provided. As shown in Fig. 6, the resilient members 34101;. supporting the bars 33 are attached at their upper 2 0fonv the disc 2I adjusted and the control ,for 'the slide 32' 7 adjusted tolimit the speed of the slide 32, the.

lapping tool I0 will be rotated L ipo'nfitslfaiis v ,TEW

1a`ppmg threaded member-s 2,379,693 reciprocatmg `member `mounted on said base for I,

movement in a direction at right angles to the axis of rotation of said spindle, a resilient member on said reciprocating member, a holder for a work piece while positioned on said spindle, said holder having an arm outstanding therefrom adapted to engage said resilient member, whereby engagement of said resilient member with said arm will oscillate said Work piece relative to said tool dur ing rotation of said spindle;

2. A machine for lapping threadedmembers rotation, a reciprocating member mounted `on said base for movement at right angles to the axis of rotation of said spindle, a resilient member on said reciprocating member, hydraulic:` means to reciprocate said member `simultaneously with rotation of `said spindle, a holder for a lwork piece While positioned onsaid spindle, said holder hav-` ing an arm outstanding therefrom adapted to engage said resilient member, whereby engagement comprising in combination, a base,ra spindle mounted for rotation therein, a lapping tool mounted on said spindle, rotating means for said spindle, means to reverse the spindle rotation after predetermined numbers of rotations in each direction, a reciprocatingmember mounted `on said base for movement in a direction at right l comprising in combination, a base, a spindle mounted for rotation therein, a lapping tool mounted on said spindle, rotating means for said spindle, means to reverse the spindle rotation, a reciprocating member mounted on said base for movement in a `direction at right angles to the axis of rotation of said spindle, means to vary the length of travel of said reciprocating member, a

resilient member on lsaid reciprocating member,

a holder for-.a work piece While positioned on said spindle, said holder having an arm outstanding therefrom adapted to engage said resilient mem` ber, whereby engagement of said resilient member with said arm will oscillate said work piece spindle.

, 4. A machine for lapping threaded members comprising in combination, a base, a `spindle mounted for rotation therein, a lapping tool relative to said tool during rotation of said mounted on said spindle, hydraulic means to rotate said spindle, means to reverse the spindle of said resilient member with said arm will oscillate said work piece relative to said tool during rotation of said spindle. Y

5. A machine for lapping threaded members comprising in combination, a base, a spindle `mounted for rotation therein, a lapping tool `mounted on said spindle, rotating means` for said spindle, means to reverse the spindle rotation after predetermined numbers of rotations, a reciprocating member mounted on said base for movement in a direction at right angles to the axis oi rotation of said spindle, a resilient member on said reciprocating member, means to vary the speed and length of movement of said member, a holder for a work piece while positioned on said spindle, said holder having an arm outstanding therefrom adapted to engage said resilient mem.. ber, whereby engagement of said resilient member with said arm will oscillate said Work piece relative to said tool during rotation of said spindle.

6. A machine for lapping threaded Ymembers comprising in combination, a base, a spindle mounted for rotation therein, a lapping too1` mounted on said spindle, rotating means for said spindle, means to reverse the spindle rotation, a reciprocating member mounted on said base for movement in a direction at right angles to the i axis of rotation ofsaidspindle, resiliently supported parallel bars .depending from said reciprocating member, a holder for a Work place while positioned on said spindle, said holder having an arm outstanding therefrom and` operating be- 1 tween said resilient bars, whereby engagement of said reciprocating member with said arm will oscillate said work piece relative to said tool during rotation of said spindle.

ALDEN M.` QDRAKE. 

